Hi!
If you were my patient, I would advise you that:
First question first, second hand smoke is not going to cause any type of birth defects as far as we know. It is best if you can avoid the smoke, and this will be even more important when you have a newborn--for both of you.
Second question:
What you have is a variant of "morning sickness" and in my opinion, the best form of it. You can lose weight guiltlessly without trying. This will not last long, but don't worry too much about it unless you are underweight already, or unless it does persist beyond 12 weeks or so.
Good luck!
Dr B
Being around smokers gives you the second hand smoke but the baby will be fine and I am saying that because i am 11 weeks and I do smoke I had my ultrasound last week and the baby had a strong heart beat. Just try not to be around it as much as possable. And as long as you are eating you and the baby will be okay its because your body is changing. As long as you eat something you will be okay, some people eat more and some eat less. Also losing weight is common in alot of pregnancies in the begining. I hope this helps a little bit, if you are really worried bring it up to your doctor when you go to see them next. congrats :)